In theory you can transfer funds any time of the day, but I have noticed that around 2-3pm gets to my bank a day sooner, after that it will show up the next day. Either way it shows up at my bank. Why rush it.

It is normally 5pm Pacific time in the U.S. For the transfer to go through at that time the next day. Anytime after that it will take over 24 hours for the funds to be send. They are always held for a minimum of 24 hours before being transferred to the bank. Also as stated above some banks take longer to process than others.